1. Field of the Invention
The present invention relates to an image display device, and more particularly to a flat image display device using an electron emitting element.
2. Description of the Related Art
Cathode ray tubes (CRT) have been used as displays using electron beams. In a CRT, image display is performed by irradiating a fluorescent substance with an electron beam emitted from an electron gun and accelerated by an anode electrode and causing the fluorescent substance to emit light. Fluorescent particles with a diameter of about several micrometers have been used as the fluorescent substance employed in the CRT.
Meanwhile, a field emission display (FED) has been developed as a flat image display device using an electron emitting element. In the FED, similarly to the CRT, image display is performed by irradiating a fluorescent substance with an electron beam emitted from an electron emitting element and accelerated by an anode electrode and causing the fluorescent substance to emit light. However, in the FED, by contrast with the CRT, a high anode voltage is difficult to apply to the anode electrode. As a result, in a case where a fluorescent substance with a particle size of about several micrometers, such as used in the CRT, is used in the FED, a sufficient emission luminance is difficult to obtain.
Accordingly, a feature of using a fluorescent substance in the form of nanoparticles as the fluorescent substrate for FED has been suggested (Japanese Patent Laid-Open No. 2007-177156).